1. Technical Field
This invention relates generally to a locking device and, more particularly, to a locking device for safely preventing the use of an electrical plug.
2. Background Art
It is often desirable to prevent the unauthorized use or misuse of electrical appliances, power tools, copiers, typewriters, or electronic equipment such as computers. By preventing this unauthorized use, damage to the equipment or injury to the user can be avoided. In the home, it might be desirable to prevent children from viewing television for extended periods of time.
In the prior art, many devices have been designed to prevent the use of electrical applicances by locking the plug on the end of the electrical cord so as to disable the plug and prevent its insertion into an electrical receptacle. Some of these devices have included a housing which could be closed over the entire plug and locked. Other devices have included a block into which the prongs of the electrical plug were inserted and locked therein. Devices of this type were complex and relatively expensive.
Simpler mechanisms have been constructed which take advantage of the aligned apertures in the plug prongs and employ conventional padlocks as locks. Examples of devices are shown in Scherer U.S. Pat. No. 3,345,600, Tunstall et al. U.S. Pat. No. 3,539,968, Drall U.S. Pat. No. 4,407,554, and Harmison, Jr. U.S. Pat. No. 4,413,488. However, the Scherer and Tunstall et al. constructions employ multiple components, while Drall and Harmison, Jr. do not prevent partial insertion of the plug prongs into a receptacle.